Terahertz nonreciprocal characteristics based on a grating metasurface

Terahertz nonreciprocal devices have achieved manipulation of terahertz waves through active control mechanisms, becoming an indispensable building block in terahertz systems. In this paper, we propose a grating metasurface that achieves high nonreciprocity of the reflection mode in the terahertz range. The metasurface structure is composed of vanadium dioxide and amorphous chalcogenide glass with grooves. Under nonlinear effects, the nonreciprocal reflectance of the proposed structure has been effectively improved, reaching up to 24.17 dB at a terahertz intensity of . It can dynamically adjust the nonreciprocal reflection performance by changing the input intensity of terahertz waves. This device achieves nonreciprocal transmission in the reflection mode without any external bias, which is beneficial for the development of terahertz-integrated nonreciprocal devices.